The invention relates generally to the field of communications, and more particularly, the present invention relates to a wireless telemetry system integrated with a broadband network such as an Ethernet local area network to provide integrated tracking, telemetry and local area networking functions.
Conventional telemetry systems exist that allow data from multiple, remotely located telemeters to be monitored from a central location. These systems typically comprise remote sensors that remotely collect the data from respective devices and transmit the data over a wireless link to a centralized monitoring station. From the centralized monitoring station, the data can be monitored in real time. The station may also include automated monitoring software for alerting an operator whenever a predetermined event occurs, such as a cardiac arrhythmia condition of a remotely monitored hospital patient.
Remote telemeters of conventional telemetry systems are generally of two types: fixed instrument remote telemeters and portable remote telemeters. For example, a remote telemeter for an ambulatory patient is a portable, battery-powered device, also referred to as a tag, which permits the physiologic condition of a patient to be monitored while the patient is ambulatory. The ambulatory telemeter attaches to the patient by a strap or other attachment device, and receives the patient""s physiologic data via ECG leads (and/or other types of sensor leads) which attach to the patient""s body. The physiologic data is continuously transmitted to the central monitoring station by the telemeter""s RF (radio frequency) transmitter to permit real-time monitoring. A design of a remote transceiver which may be used in a two-way, ambulatory telemeter is described in U.S. Pat. No. 5,944,659 to Flach. Examples of fixed instrument remote telemeters include patient telemeters that operate in a similar manner to those described above, but receive the patient""s physiologic data from a bedside monitor (or other instrument) over a hardwired link, such as an RS-232 connection. Instrument remote telemeters that transfer the physiologic data to the central station over a hardwired connection are also common.
While such devices are useful for monitoring various conditions of remote objects and persons, e.g., the condition of a patient, they have associated disadvantages. First, typical transceivers in these systems rely upon space, time and frequency diversity schemes to overcome the effects of multi-path interference when transmitting data from a remote device to a monitoring station. Multi-path interference is particularly problematic for intra building transmissions. Implementing diversity schemes such as those mentioned increases the cost, size and complexity of a system. In addition, in at least some implementations, a loss of data may occur when a xe2x80x9cswitch-overxe2x80x9d is performed from one antenna/receiver pair to the other. Another problem encountered in typical distributed antenna systems is that they are typically highly vulnerable to isolated sources of electromagnetic interference (EMI). Specifically, because the signals received by all of the antennas are combined using RF signal combiners, a single source of interference (such as a cellular phone or a faulty preamplifier) at or near one of the antennas can introduce an intolerable level of noise into the system, potentially preventing the monitoring of all patients. One consequence of this problem is that antennas generally cannot be positioned near known intermittent sources of EMI such as X-ray machines, CAT (computerized axial tomography) scanners, and fluoroscopy machines, preventing patient monitoring in corresponding diagnostic areas. Accordingly a need exists for telemetry systems capable of operating reliably indoors with minimal interference and without the need for complex or redundant hardware.
It is frequently desirable to precisely locate and track a remote object whose condition is being monitored. However, while coarse positioning (calculating the position of an object with an accuracy of about a few yards) is possible with existing systems, these systems are not suitable for accurate location and tracking of the remote telemeters from which they receive data. Conventional direction finding devices exist that locate persons and objects more precisely using triangulation techniques and appropriate transmitters. However, these require additional dedicated hardware, and thus a separate infrastructure from the remote monitoring application. Further, these systems may not be accurate in all conditions, especially in severe multipath environments.
Local area networks for sharing data and application programs, i.e., xe2x80x9capplicationsxe2x80x9d among users are common in hospitals, offices and commercial and industrial facilities. LAN architecture provides for a plurality of nodes, typically comprising personal computers, configured to run one or more user applications. The computers are typically interconnected by an infrastructure comprising a broadband link such as Ethernet. The LAN infrastructure includes cabling distributed throughout the facility such that all the computers are coupled to one another. When upgrading a facility to include such capabilities as telemetry, remote monitoring and tracking, it would be desirable to integrate the upgraded capabilities with existing LAN infrastructure within the facility. Accordingly, there is a need for an integrated communications network capable of performing conventional LAN applications and functions while carrying out telemetry, monitoring, and tracking functions.
A communications system comprises a broadband subsystem comprising at least one UWB node including a first UWB transceiver and at least one application node linked to the UWB node by a broadband link. The system further comprises a wireless subsystem comprising at least one remote communicator, the remote communicator including a second UWB transceiver. The first and second UWB transceivers are configured to communicate with each other via an UWB communications link.